Door control



Jllly 22, 1941. F RBEAL 2,249,932

DOOR CONTROL Filed Dec. l0, 1938 .4 TTORNE Y6 Patented `uly 22, 1941 UNITED STATES'HTPATENT OFFICE DOOR GQNTROL Francis R. Beal, Port William, Ohio Application December 10, 1938, Serial No. 245,032

11 Claims. n.(yCl. 268-74) This invention relates to automatic means for controlling the opening and closing movements of oppositely swinging doors, and, more particularly, for controlling said movements of such doors hinged about horizontal pivots.

The invention has particular application to horizontally pivoted oppositely swinging doors of commercial truck bodies. In the employment of trucks for ordinary delivery purposes, it is advantageous to utilize truck bodies provided with doors mounted so as to move about horizontal pivots, since such doors, when opened, do not extend outwardly beyond the confines of the body so as to impede the passage of other vehicles in narrow streets. Furthermore, the use of horizontally pivoted doors has additional advantages in that the lower door, when opened, may, when held in a horizontal position, be used as a platform to facilitate loading of the truck, an-d the upper door, when opened outwardly in a horizontal position, provides protection from the weather during the loading process.

The use of vertically swinging doors, in common practice, has certain disadvantages which the present invention has been designed to overcome. Under present practice, the vertically swinging doors of commercial trucks are in no way inter-related and must be opened and closed separately. The doors are ordinarily of heavy construction so that their opening and closing requires considerable physical exertion. Moreover, the operation of opening the upper door commonly requires that the operator climb upon the truck platform and reach up to push the heavy upper door upwardly into its fully opened position. This is ineicient and inconvenient.

The present invention enables the operator to control the opening and closing of both doors, in a simple and eicient manner, by operation of the lower door from a convenient position when standing upon the ground. By the use-of the present invention, the physical exertion, required to open and close the doors, is greatly reduced because of the fact that the weight of each door is balanced respecting the other. y Y

It is an object of the present invention to provide means for inter-relating a plurality of movable doors in such a manner that the movement and positioning of all is effected and controlled by the operation of one.

Another object of the invention is to provide means for inter-relating a plurality of horizontally pivoted doors in such a manner that the gravitational force of each is balanced respecting the gravitational force of the other -so as to assist exterior forces applied to one of them in effecting desiredmovements and desired positioning of said doors.

Another object of the invention is to provide means for inter-relating a plurality of movable doors in such a manner that the gravitational force of either may be caused to over-balan-ce the gravitational force of the other to effect oertain desired movements, or maintain cer-tain desired positions, of said doors.

In carrying the invention into practice, I have provided instrumentalities for inter-connecting a plurality of doors, which instrument-alities are so designed that the gravitational forces of said doors are in balance under certain conditions and over balanced, one against the other, u nder certain other conditions. These results are accomplished by providing inter-connecting instrumentalities which enable the gravitational force of either door to exert an advantage over the gravitational force of the other door, depending upon the desired movement and positioning of the doors.

In the exemplication of the invention, herein shown and described, the objects and purposes thereof are accomplished by the use of interconnecting instrumentalities, consisting of a system of links and levers, but, it is to be understood, the invention contemplates the use of other instrumentalities having equivalent functions Within the scope of the appended claims.

Other advantages, objects and features of novelty -of the invention will appear more fully as the detailed description of the invention progresses in conjunction with the drawing in which:

Figure 1 is a side View of the rear end of a commercial truck, a portion of one of the side walls thereof being broken away to show the instrumentalities by vwhich the doors are interconnected.

Figure 2 is a top view sh-owing certain of said instrumentalities.

Figure 3 is a view, similar to Figure 1, showing a modincation of the invention.

lFigure 1 illustrates a commercial truck body comprising a frame and side walls and having an opening at its rear normally closed by vertically swinging upper and lower doors.

The numeral I designates a truck body provided at its rear with an upper door 2 hinged to a frame la about a horizontal pivot 3, and a lower door 4 hinged to said frame about a horizontal pivot 5.

The upper door 2 has attached thereto a bracket 6 to which is' connected a force direction changing device which, in this instance, comprises a link 'I, said link beingr pivotally connected, as at 8, to said bracket. Associated with said force direction changing device is a force multiplying device, generally designated A, and, in the present instance, taking form of a lever consisting of the arms Il and Ill. Extending between said arms is a brace member II. The said force multiplying device A is fulcruined at I2, being at such point pivotally connected to a supporting bracket I3 rigidly secured to a horizontalV strut I4 comprising a part of the inner frame structure of the truck body I.

The lever arm 3 is pivotally connected, as at I5, to the link 'I. Associated with the force Ymultiplying device A are force direction changing instrumentalities, now to be described, which are also associated with the lower door 4. The lastmentioned force direction changing instrumentalities comprise a rod or link I6, a force multiplying device or lever B,`and the links I'I and I8. The link or rod I is pivotally connectedas at I9, to the lever arm III, and said link is alsopivotally connected, as at 2i), to one arm `2I of the lever B.

The lever B is fulcrumed, as at 22being at such point pivotally connected to a strut 23 secured to the vertical posts 24 and 25 of the truck body frame structure. The other arm 25 of said lever B is pivotally connected, as atv 21, to the link I'I, which, in turn, is pivotally connected, as at 28, to the link I8. Said link I8 is pivotally connected as kat 29, to the lower door 4.

It will thus be seen that the instrumentalities, interconnecting the doors 2 and 4, primarily comprise two sets of force direction changing instrumentalitiesass'ociated with the force multiplying device A:

In the construction, just described, one setof force direction changing instrumentalities interconnects the upper door 2 withthe force multiplying device or lever A. These force direction changing instrumentalities comprise the link 'I and its associated pivotal connections B and I5Y by which they are interconnected with said door 2 through said bracket 6 and with said lever A through the arm 9.

The second set of lforce direction changing instrumentalities, as before mentioned, comprises the members I8, B, II and I8 and their respective pivotal connections IS, 2G, 21, 23 and 29 by which the component parts of said instrumentalities are interrelated and associated with the door 4 and the lever A. Y

While the primary function of the second set of force direction changing instrumentalities is to change the direction of application of the gravitational force of the lower door 4 they have a secondary force multiplying function through the lever B, whichv is, however, not essential to the operation of the invention, as will be more fully dealt with hereinafter.

In operation, the doors 2 and 4 are caused to be moved from their fully closed positions, indicated by dotted lines in Figure-1, to their fully opened positions, as shown in said figure, by exerting an outward pull upon the handle 30 of the lower door 4.

When the said doors are fullyclos'ed, as indicated by the dotted lines,'their inter-connecting instrumentalities will assume the positions, indicated bythe broken lines in Figure 1.

Thus it will be seen that when an outward pull through the handle 30 is exerted upon the lower door 4 the force, ,so applied, will pull the links yII;and I8 outwardly, rotating the leverBin a clockwise direction around its pivot 22, and causing the link I5 to be moved downwardly. This' causes the lever A to be rotated in a counterclockwise direction about its pivot I2, and this exerts an outward thrust upon the link 1, causing the upper door 2 to be moved upwardly about its pivot 3.

It is thus to be seen that at the beginning of outward movement of the door 4, the force applied thereto is transmitted to the upper door in a horizontal direction. Immediately after the beginning of movement of the lower door, the direction of application of the force applied thereto is changed so as to apply said force in a vertical direction to the upper door 2.

When the doors are in their fully closed positions, the gravitational forces thereof are applied, through their respective pivotal connections, directly to the frame of the truck body. As the lower door moves outwardly, the link 'I exerts van outward thrust upon the upper door and the direction of application of the gravitational force thereof is changed so as to resist counterclockwise movement of the lever A. Meanwhile, the direction of application of the gravitational force of the lower door is changed so as to exert an ever-increasing outward pull upon the linkage I'I-IS. `As the doors move further outwardly, the direction of application of the gravitational force of the upper door is gradually changed so that it is applied more and more in thedirection of the length of arm 9 rather than at right angles thereto. The resistance of the upper door to movement of lever A, therefore, becomes less and less.

At a certain point, therefore, in the movement of the doors between closed and opened positions, the gravitational force of the lower door will be greater than the resistance of the gravitational force of the upper door to the movement of the lever A, whereupon the weight of the lower door will, of itself, be suiiicient to carry both doors to open position without further application of exterior force to the lower door.

Because of Vthe break in the linkage I'l-IE, resulting from their pivotal connection 28, the lower door-is enabled to move downwardly past its horizontal position, shown in Figure l, to the lower dotted line position, shown in said figure, without further effect upon the movement of the upper door after Vsaid lower door reaches said horizontal position. In other words, the effect of the gravitational force of the lower door reaches its peak, respecting its effect upon the movement of the upper door, when the lower door reaches the horizontal position of Figure `l. At such time the upper door 2 is fully opened.

Since it is advantageous, under certain conditions, that the bottom door 4 be permitted to drop down to the `lower dotted line position, the break linkage II-I8 vis utilized for the purpose of permitting the lower door to drop to said lower dotted line position. Of course, if it is desired to utilizethe bottom door 4 as a platform to facilitate loading, said door may be maintained in horizontal position by means of the chain'3l.

When the doors are in their fully opened positions, shown in Figure 1, and it is desired to restore the same to their closed positions, the operator has merely to lift up the lower door 4 and bothdoors vwill be moved to closed position. When the lower door is moved upwardly, this movementisftransmitted through the inter-connecting linkage to the lever A, causing the-same to move in a clockwise direction. In so doing, it will be seen that the force resisting clockwise movement of lever A is diminished and the gravitational force of the upper door `tending to cause such movement now does so. As the doors move toward closed position the direction of application of the gravitational force of the upper door is gradually changed so as to be applied more and more in a direction at right angles to the length of arm 9.

Thus, the weight of the upper door 2 exerts an ever-increasing force, moving the lever A in a clockwise direction, as the lower door 2 is lifted upwardly. Consequently, as the doors pass the point in the arc of their movement toward closed position, at which time the gravitational forces of said doors are in balance, throughltheir interconnecting instrumentalities, the gravitational force of the upper door 2, acting upon the lever arm 9 in a clockwise direction, will be greater than the resisting gravitational force of the lower door 4. This is due in part to the fact that the full weight of the lower door is not being applied to pull the linkage l'l-IB outwardly but is exerted directly upon the frame through pivot 5.

When the doors pass said point in their movement toward closed position, the weight of the upper door will carry both doors to closed position without any further application of lifting force upon the lower door,

A modification of the invention, respecting the lower force direction changing instrumentalities, is shown in Figure 3. In said figure cable and pulley means have been substituted for the links and levers, inter-connecting the lever A with the lowerdoor 4. In said figure the lower force direction changing instrumentalities comprise a pulley 32 rotatably mounted upon the strut 23 and a cable 33, trained over said pulley, one end of which cable is secured, as at 19a, to the outer end of arm II of lever A, and the other end of which cable is secured, as at 29a, to the lowerdoor 4.

In the modification, just described, the manner of operation of the instrumentalities, effecting simultaneous opening and closing of the upper and lower doors, substantially corresponds with the operation of the construction previously described.

It will be noted that the cable 33 has the same capability, that the break linkage l'l-l8 has, to permit the lower door 4 to be dropped past its open horizontal position shown without further affecting movement of the upper door. The link I1 comprises a tubular portion lla which is internally threaded and into which screws the externally threaded rod portion 11b. The operating length of the link I1 may then be adjusted as required.

From the above description it will be seen that the present invention provides means for effecting the opening and closing movements of both upper and lower doors simultaneously as a result of the operation of the lower door and that the said opening and closing movements will, at all times, be under the control of the operator through his manipulation of the lower door.

It will, furthermore, be seen that the inter-connecting instrumentalities of the present invention have many advantages. Among these are simplicity, eiciency and ease of operation. The simultaneous opening and closing of the doors saves the operators time since it eliminates the necessity of, vand hardship involved in, reaching upto push the upper door into open position. By reason of the fact that the gravitational forces of both doors, under all conditions, to a lgreater or less extent, oiset one another, the operation of opening the doors requires the application of less force than would be involved in the opening of the upper door alone were the inter-connecting instrumentalities of the present invention not utilized.

Similarly, the operation of closing both doors, assuming that the lower door is in a horizontal position, requires the application of less force than would be required to raise the lower door alone from its horizontal open position to closed position, without the employment of the interconnecting instrumentalities of the invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In closure operating means of theY classdescribed, the combination of a support, a pair of doors pivotally connected thereto, and operating means connected to the doors and to the support for actuating one door from the other, said operating means including a flexible connection connected to one of the doors and arranged to move into contiguous relation to the axis of swing of the said door, said combination including means in the path of such movement to impede the same and thereby cause such connection to ex about the pivot of the door and thereafter permit movement of said door independently of any effect upon the other door.

2. In closure operating means of the class described, the combination of a support, a pair of doors pivotally connected thereto, and operating means connected to the doors and to the support for actuating one door from the other, said operating means including a flexible connection connected to one of the doors and arranged to iiex about the pivot thereof to permit movement of said vdoor independently of any eiect upon the other door, said flexible connection comprising pivotally connected links arranged to be shifted by its connected door into a position such that the pivotal connection between said links is immediately proximate to the axis of said door in the opening movement thereof to thereby cause the door to swing about the connection of the links as an axis substantially concurrently with the pivotal axis of said door whereby further movement of the last-mentioned goor may be produced independently of the other oor.

3. In closure operating means of the class described, the combination of a support a door pivotally connected thereto, a second door for operating the first-mentioned door, and operating means connecting the two doors to the support and to each other, including a flexible connection connected to the second door, said operating connection effecting corresponding 'move- .ment of the two doors upon actuation of said eratingthe first-mentioned door, and operating means connecting theY two doors tothe support and to each other, including a flexible connection connected to the second door, said operatingconnection effecting corresponding movement of the two doors upon. actuation of said second door throughouta predetermined arc of movement thereof, said exible connection permitting further movement thereafter of the second door independently of any eiect upon the rst door, said exible connection comprising a pair of links having an offset pivotal-connection movable into a position immediately proximate to the axis of the second door whereby to permit the latter to swing about said pivotal connection and said axis as substantially concurrent axes to discontinue movement of the rst door and permit further independent movement ,of said second door.

5. In closure operating means of the classdescribed, the combination of a support, a pair of doors pivotally connected thereto vand operating means connected to the doors and to the support for actuating one door from the other, said operating means including a flexible connection connected to one of the doors and arranged to flex about the pivotthereof to permit movement of said door independently of any eiect upon the other door, said operating means including a cable connected to one of the doors and passing about a pulley in position to iiex about thepivot of its connected 4door when said door is moved independently of any effect upon the other of the pair of doors. ,l v

6. In closure operating means oi the class described, Ythe combination of a support, upper and lower doors pivoted thereto to swing vertically, means to operate one door from the other` comprising a pair of bell crank levers connected to the support in spaced relation, one of said levers having a long arm-and a short arm, a link connecting the long arm to the upper door, a con-l v ranged so that when the lower door is swung -to open position, the effective leverage action of its connection to the associated bell crank increases while ythe effective leverage action of lthe link to the long arm of the other bell crank decreases thereby tending to hold the` doors in open position under gravitational action of the lower door, said connecting means betweenl the lower door and its associated bell crank consisting of a pair of pivoted links arranged to flex about the pivot of the lower door to permit movement ofthe lower door independently of the upper door. Y

7. In closure operating means of the class described, the combination'of a supporta pairof doors pivotally connected thereto, and operating means connected to the doors and tothe support for actuating one door from the other,.said operating means including a exible connection connected to one of the doors and disposed remote from theV pivot of said last mentioned door when the doors are closed, and shiftable by the door to which it is connected during the opening movement of said door to a point immediately proximate the pivot of said last mentioneddoor to flex at said point to permit movement ci"` said door independently of any effect upon Athe other door.

vscribed,`the combination of arsupport, a' pair vof doors .pivotally mounted `thereon to swing about horizontal axes one above the other, and operating means-for actuating one door from another comprising a pair of connected levers, Aeach having angularly `disposedarms, a link connecting one armof one lever to one of said doorsa second Vlink Vconnectingonearm ofthe other lever to the other .door, said door connecting means `and levers being so constructed and arranged that the angle between the rst link and the arm of the lever to which it is connected is less than a right Aangle when the vdoors are in closed pOSition and `substantially astraight angle when the doors are fully open, and the angle between the second link and the arm of Vthe lever to which it is connected `is less-than a right angle when the doorsare in closed position and approximatelyra right angle when the doorsarein fully open position, whereby vwhen said doors are in closed position gravitationalaction of one door holds said doors in fully closed position, and when the doors are in open position gravitational laction of the other door holds said doors in fully open position.

9. In closure operating means of the class described, the combination of .a support, a pair of doors pivotally mounted thereon to swing about horizontal axes one above the other. and Operating means for actuating one door from another comprising a pair of connected levers, each having a fulcrum and actuating vpivot points, the angle formed by the fulcrum and pivot points of the first lever being less than a right angle, the angle formed by the fulcrum and pivot points of the second lever being substantially a right angle, a link connecting a pivot point of the first lever to one of said doors, a second link connecting a pivot point of the other lever to the other door, said door connecting means and levers being so constructed and arranged that the angle formed by the fulcrum of the rst lever and the pivot points of the iirst link with said lever and its connected door is less than a right angle when vthe doors are in closed position and substantially a straight angle when the doors are in f ully open position, and the angle formed by the fulcrum of the second lever and the pivot points of the second link with said second lever and its connected door is less than a right angle when the doors are in closed position and approximately a right angle when the doors are in fully open position, whereby when said doors arein closed position gravitational action of one door holds said doors in fully closed position, and when the doors are in open positiongravitational action of the other door holds said doors in fully open v position.

10. In a door operating mechanism, a support, a pair of horizontally pivoted doors carried by said support and arranged to swing from a vertical position to spaced substantially parallel positions one above the other in horizontal planes, and operating means for actuating one door from another comprising a plurality of connected force and travel changing devices, each of which is connected to one of` said doors, one of said devices operating to exert increasing leverage action upon its connected door, and the other of said devices voperating to exert decreasing leverage action upon its connected door when the doors are moved from closed to open position, the action of the respective devices upon their respective connected doors being reversed when the doors are moved in anV opposite direction wherev by when said doors are moved from closed to openv positions'thev gravitational force. of the first door will be caused to over-balance the gravitational force of the second door when the first door reaches a point about midway between its open and closed positions and thereafter cause said doors to move to their fully opened positions without further application of external force to either of said doors, and when the doors are moved from open to closed positions the gravitational force of the second door will be caused to overbalance the gravitational force of the iirst door when the latter reaches said 'point and thereafter cause said doors to move to their fully closed positions without further application of external force to either of said doors.

11. In a door operating mechanism, a support, a pair of horizontally pivoted doors carried by said support and arranged to swing from a vertical position to spaced substantially parallel positions one above the other in horizontal planes, and operating means for actuating one door from another comprising a plurality of force and travel changing devices, each of which is connected to one of said doors, one of said devices operating when the doors are moved between open an-d closed positions to exert progressively increasing leverage action upon its connected door and also operating at rst to progressively increase the degree of travel ofits connected door relative to the other door until one of said doors reaches a point about midway between open and closed positions, and then subsequently to progressively decrease the degree of travel of its connected door relative to the other door as the doors continue to move in their original direction, the other of said devices operating to exert progressively decreasing leverage action upon itsI connected door and also operating at rst to progressively decrease the degree of travel of its connected door relative to the other door until one of said doors reaches a point about midway between open and closed positions, and then subsequently to progressively increase the degree of travel of its connected door relative to the other door as the doors continue to move in their original direction whereby when said doors are moved from closed to open positions the gravitational force of the irst door will be caused to overbalance the gravitational force of the second door when one or the other of said doors reaches said point and thereafter cause said doors to move to their fully open positions without further application of external force to either of said doors, and when the doors are moved from open to closed positions the gravitational force of the second door will be caused to overbalance the gravitational force of the rst door when one or the other of said doors reaches said point and thereafter cause said doors to move to their fully closed positions without further application of external force to either of said doors.

FRANCIS R. BEAL. 

